Turning your car engine over by hand isn’t as simple as just reaching under the hood—you’ll need a large socket, and a long ratchet wrench to get the job done. The best way to turn your engine over is to place the socket on the front of your engine’s crankshaft bolt, which is typically mounted to your crankshaft; then take your wrench and use it to manually roate the crankshaft (turning the wrench in a clockwise motion).
For some engines, you can also try tautening the power steering pump belt, then rotating the nut on the front of your pump to manually turn the engine. However, to do so you’ll first need to extract your car’s spark plugs—so it’s best to try the first method first!